• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.42-53
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• 2015

In order to assess the hydraulic effects of flow pattern changes and geomorphological evolution around spur dikes, this study carried out monitoring and numerical simulation on the changes of morphologic characteristics around spur dikes that settled in the bend of the Yeongcheon River. The study site spanned 190 m, and spur dikes were installed in March 2008. Monitoring of the site started in May 2008 and was completed in April 2014. When the water level was higher than the height of the spur dikes, the spur dikes extrude flow from the bank. Therefore, the spur dikes that were built to stabilize the channel have been effectively performing hydraulic functions. With the passing of time, the channel was stabilized and pools formed around the spur dike toes by local scouring. It was confirmed that spur dikes created various physical characteristics in the aspect of channel topography, with sediments deposits occurring between the spur dikes, while riffles and pools formed in the channel.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.258-262
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• 2009

A Practical application of environmental monitoring system based on wireless sensor node network with the core of embedded system STR711FR2 microprocessor is presented in the paper. The adaptable and classifiable wireless sensor node network is used to achieve the data acquisition and multi-hop wireless communication of parameters of the monitoring base station environment including repeaters. The structure of the system is proposed and the hardware architecture of the system is designed, and the system operating procedures is proposed. As a result of field test, designed hardware platform operated with 50kbps bit rate and 5MHz channel spacing at 2040Hz. The wireless monitoring system can be managed and swiftly retreated without support of base station environmental monitoring.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.75-85
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• 2006

In recent geotechnical engineering, geothermal approach has been on the horizon to deal with geoenvironmental issues, freezing and thawing problems, and seepage phenomenon in dams and embankments. In this study, geothermal characteristic through inner body of dams and its influence on the seepage flow were experimented by lab test and field instrumentation. Also, one of up-to-date temperature monitoring technique, called as multi-channel thermal line sensing, was evaluated its availability. As a result of lab test, it is found that the seepage flow has influence on the geothermal characteristic and a potential of finding phreatic line and seepage fluctuation could be possible by continuous temperature monitoring using thermal line sensing skills. These kine of geothermal information could be available to the modelling of water geo-structure interaction. Out of short-term field tests, clear water table and temperature distribution of a dam were easily found through temperature monitoring in holes located near a reservoir and holes within a depth of constant temperature layer. However, it is also found that the geothermal flow and finding seepage line could not be easily understandable through multi-channel temperature monitoring because of the existence of constant temperature field, thermal conductivity of soils and rocks, and unsaturated characteristics of geo-material. In this case, long-term geothermal monitoring is recommended to find sudden fluctuation of seepage line and amount of leakage.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1211-1218
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• 2005

Temperature variation according to space and time on the inner parts of engineering constructions(e.g.: dam, slope) can be a basic information for diagnosing their safety problem. In general, as constructions become superannuated, structural deformation(e.g.: cracks, defects) could be occurred by various factors. Seepage or leakage of water through these cracks or defects in old dams will directly cause temperature anomaly. Groundwater level also can be easily observed by abrupt change of temperature on the level. This study shows that the position of seepage or leakage in dam body can be detected by multi-channel temperature monitoring using thermal line sensor. For this, diverse temperature monitoring experiments for a leakage physical model were performed in the laboratory. In field application of an old dam, temperature variations for water depth and for inner parts of boreholes located at downstream slope were measured. Temperature monitoring results for a long time at the bottom of downstream slope of the dam showed the possibility that temperature monitoring can provide the synthetic information about flowing path and quantity of seepage of leakage in dam body.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.3
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• pp.197-202
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• 2010

In this paper, multi-channel vital signal monitoring system was implemented for home healthcare. The system able to measure vital signal for example ECG, PPG and temperature simultaneously at patients’ home. The vital signal is an essential parameter for healthcare application and can be easily extracted from patients. The implemented system consist of sensor parts for signal extraction, signal amplifier and filter for analog circuit, analog signal to digital conversion for controlling devices and lastly the monitoring program. The system able to transmit vital signals using Bluetooth wireless communications to personal computer or home server. And the tele-monitoring system able to display real-time signals using web monitoring program. In medical application, the vital signal parameter able to stored and saved in the web server for further medical analysis. This system opens up the possibilities of ubiquitous healthcare where further implementation can be easily done.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1275-1282
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• 2012

This paper proposes the 16-channel LED Driver IC for Full color LED display system. The proposed LED driver IC in this paper can draw current independent of temperature and supply voltage in each channel. Current flow in the channel is configurable via an external resistor. LED brightness is adjusted by 12-Bit PWM(Pulse Width Modulation) and 8-Bit DC(Dot Correction). A real-time monitoring of IC temperature ($130^{\circ}C/150^{\circ}C$) and LED status (open/short) is provided by LED driver IC and the user can receive warning and get information on problems. A 16-channel LED driver IC is produced using 0.35 um BCD process and the size is $2.5mm{\times}2.5mm$. In this paper, channel current characteristic and channel current control function were measured in order to verify am embodied 16-channel LED driver IC by producing a single IC test board.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.3
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• pp.71-87
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• 2007

In order to improve and manage rationally for Youngdam creek in Haman-gun, the channel change, water quality and ecological adaptation etc. were evaluated by monitoring during three years. The distinct differences of channel characteristics appeared in the extents of bed excavation and the revetment methods because overall reconstruction was occurred intense disturbance of width expansion and levee construction etc. The scour and deposition were caused according to channel characteristics of ripple and pool, and the adaptation of vegetation was distinguished from each revetment methods clearly. Water quality was maintained first class on the basis of BOD as 0.5~1.5mg/${\ell}$. The vegetation appeared in 380 species close-to-nature river improvement before, but 64 species it after one year, 159 species it after two year and 158 species it after three year. The animal life appeared in 123 species of close-to-nature river improvement before, but 103 species it after one year, 116 species it after two year and 119 species it after three year.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.185-193
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• 2014

In this paper, we developed a 4-channel particle counter for measuring particles, temperature, humidity in production facilities of clean-room environment, and the measured data can be transmitted via bluetooth. To measure the particle size ranging 0.3um~5um, we designed optical lens, particle detection chamber and multi-channel particle detection circuit. And we also developed a FMS program for real-time monitoring of measuring data, which resulted in the stable operation.

• Journal of Sensor Science and Technology
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• v.26 no.1
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• pp.1-6
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• 2017

The advanced driver assistant system (ADAS) requires the collection of a large amount of information including road conditions, environment, vehicle status, condition of the driver, and other useful data. In this regard, large-scale sensor networks can be an appropriate solution since they have been designed for this purpose. Recent advances in sensor network technology have enabled the management and monitoring of large-scale tasks such as the monitoring of road surface temperature on a highway. In this paper, we consider the estimation and fusion problems of the large-scale sensor networks used in the ADAS. Hierarchical fusion architecture is proposed for an arbitrary topology of the large-scale sensor network. A robust cluster estimator is proposed to achieve robustness of the network against outliers or failure of sensors. Lastly, a robust hierarchical data fusion scheme is proposed for the communication channel between the clusters and fusion center, considering the non-Gaussian channel noise, which is typical in communication systems.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.746-751
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• 2006

The geumjunggu of the onchunchun which is the upper stream have been maintained as a too much picture to become a concrete lining about existing low flow channel and the reservoir water protecting banks for the reason of the flow of an upper stream steep slope and back of the shortage of the channel area in a suitableness interval. This research made a rating-curve to decide since to ensure against risks to the flood control through the undo of the rivers. And we found the speed of current of a nature undo interval and existing concrete interval and water level change out. A result from this natural disposition we must apply as a data for the research about the plan to be established in the rivers maintenance basis plan of onchunchun.